School-chair



(No Model.)

0. C. CLARK.

" SCHOOL CHAIR.

No. 275,021. Patented Apr. 3, 1883. a

- Wzmms. v JWV/fim 4 I UNITED STATES PATENT OFFICE.

OGDEI O. CLARK, OF NEWTON, MASSACHUSETTS.

SCHOOL-CHAIR.

SPECIFICATION forming part of Letters Patent No. 275,021, dated. April 3, 1883.

Application filed January 2, 1883. (No model.)

T 0 all whom it may concern Be it known that I, OGDEN CLARE CLARK, a citizen of the United States, residing at Newton, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in School-Chairs; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference heinghad to the accompanyin g drawings, and to letters or figures of reference marked thereon, which form apart of this specification.

This invention relates to swiveled seats for school-desks-that is, seats employed independent of the desks, and adapted to turn about a pivot in order that their position may be changed.

My invention consists in the peculiar construction of the pivot which connects the chair 7 with its supporting-pedestal, the object of my invention being to obtain a-strong and dura ble connection between the seat and its support and prevent loosening and rattling of the parts, as well as to euablethe seat to be changed in position to enable a student to readily seat himself at his desk or get up from the same.

The drawings accompanying this specification represent in Figure 1 a side elevation of a school-desk in connection with a seat or chair containing my invention. Fig. 2 is a vertical section, and Fig. 3 a horizontal section, of the joint between the chair and pedestal. Fig. 4 represents a vertical section through a pedestal and hub provided with a modification of my devices for increasing friction.

In said drawings, Arepresents a school-desk, and B the chair of the same. such chair being independent of the desk, but disposed permanently in rear of the latter.

In carrying out my invention I employ an upright pedestal, G, which is partially recessed at top to receive a circular hub or tenon, D, extending downward from a plate, E,.which is secured to the under side of the chair-seat F. The connection between the hub D and the pedestal U is as follows: I erect upon one side of the top of the pedestal a curved ledge, G, which incloses a part of said hub, and I form upon the periphery of the hub a rib, a, which enters a corresponding groove, b, in the inneri face of the ledge G. The ledge G preferably; The hub from the pedestal, while the ledge G serves, in

a great measure, to confine the hub and chair to said pedestal.

.To prevent too ready turning of the chair upon its support, I employ a friction device in the form of awasher,I-I,of spring metal,.which is introduced between the top of the plateE and the chair-seat, and retained in place by a screw or bolt, 0, the friction being increased or diminished according to the pressure brought to bear upon the plate H by said' bolt.

This construction may be modified, as shown in Fig. 4 of the drawings, in which I have shown the pedestal O of the ordinary construction. To prevent any change in the position of the screw 0 and loosening thereof, and consequently too free play of the chair on the pedestal,I have formed said bolt with a square shoulder, e, which snugly fits the top portion of the pedestal, the remaining part being cylindrical, and provided with a screw-thread and nut on its lower end. It will therefore be readily seen that after the nut has been adjusted in a position such as to produce the requisite friction by drawingtheplateH against the l1 uh D of the chair-seat, said bolt must remain in a fixed position, owing to said shoulder, and as the entire wear and strain comes entirely upon the Tibet and portion G of the pedestal said bolt will remain intact and undisturbed so long as the chair is used, except when it may be tightened to compensate for loss in wear by friction on the bearing-surfaces or diminishing the stress of the spring-washer I raised semicircular ledge, in combination with H, and consequently the degree of friction between the chair and its support. Owing to the large surfaces of the hub and the pedestal, a firm and steady bearing is obtained and wear greatly reduced.

Heretofore in ,the construction of schooldesks the seats of the chairs have been incapable of rotation, and are necessarily placed so far from the desk, to permit the student to occopy and leave them, that the desk is too far away. By swiveling the chair-seat, as I propose, it may be turned to one side to permit the student to occupy it, and can for this reason he placed nearer the desk than if immovable.

To provide stops to determine the extremes of rotary movement of the chair-seat, I secure to one side of the hub D an abutment, c, which operates with the ends of the ledge G;

I claim- A pedestal provided on its top with a a chair-seat which is provided with a hub extending downward into the space within said ledge, said hub being pivoted to said pedestal, and havingalateral extension which protrudes into the open space between the ends of said ledge, substantially as set forth.

2. The pedestal 0, having a raised semicircular ledge, G, provided with a horizontal groove on its inner face, in combination with a chair-seat, and a hub, D, attached to said seat and pivoted to said pedestal, said hub having a rib or head which fits said groove in ledge Gr, substantially as set forth.

In testimony whereof Iatfix mysignature in presence of two witnesses.

OGDEN CLARE CLARK.

Witnesses:

H. E. LODGE, M. D. PORTER. 

